With regard to this kind of clutch brake, the applicant of the present invention has heretofor developed a clutch brake, as illustrated in FIG. 6, and has applied for a patent (Japanese application No.: 61-46786, Date of application: Mar. 4, 1986 corresponding U.S. patent application Ser. No. 021,066, filed Mar. 3, 1987, now U.S. Pat. No. 4,782,926, dated Nov. 8, 1988).
In such prior clutch brake, a coned disc spring 100 is interposed between a cover assembly C and a brake assembly B so as to improve the torque characteristic produced by the brake assembly B. However, even though an inertial torque working on an output shaft (connecting to a transmission equipped with no synchro mechanism) increases with an increase in a rotation speed, a brake torque can not be increased with an increase in the rotation speed.
Further, the engagement action at time of increased rotation speed is done abruptly, so that facings 110 will be worn out quickly.